1. Field of the Invention
The field of the invention is that of taps for making tapped holes and quick change tap holders as used with the taps.
2. Description of the Prior Art
The art of taps for making tapped holes, quick change holders or adapters for taps, and tapping apparatus, that is, tapping attachments, is well-developed.
A need exists, however for improvements, and this need will be addressed herein.
In the industry, both domestically and abroad, there is a great variety of tapping apparatus or tapping attachments, and particularly, there is a great variety of taps as to styles, thread sizes (inch and metric), over-all lengths, shank and square sizes, to a variety of standards, American, British and Metric. What is not available is what might be called an international standard tap or tap blank which would accommodate itself to the great variety of needs for a tap. This is a need, the filling of which would be of very substantial benefit to the industry.
There is presently available quick change holders or adapters for holding taps, the adapters being constructed for quick change from one tap to another of the same size. The holders or adapters serve the purpose of accommodating the tap to be driven to a particular machine, such as a drill press or a tapping attachment. Typically, in the known art, the shank of the tap is held in the holder or adapter by way of circularly arranged balls that press in radially directly against the cylindrical surface of the shank of the tap. A disadvantage exists in this construction in that the holding force that can be applied is limited and the possibility of slippage or accidental pull-out.
A very great advantage would be if all thread sizes of taps, both U.S. standard and British standard, and metric standards could be made on or from the same blanks, and all would have the same overall length and shank diameters and squares, it could truly be an international standard for CNC applications, that is, Computer Numerical Control applications. The need for realization of these advantages, the object of realizing these advantages, and the actual realization appears hereinafter.
A preferred form of the herein invention appears hereinafter, the invention being intended to fill the needs referred to in the foregoing, as well as other needs.